Costumes At The 2011 Tokyo Marathon, Japan

History
The first Tokyo Marathon was held on 18th March 2007. However, years prior to 2007, Tokyo Marathon actually consisted of two marathons - the Tokyo International Marathon which took place on even years, and Tokyo - New York Friendship International Marathon which took place on odd years. In the inaugural year, 1981, both marathons took place. However, because it was not possible to support two marathons a month apart in the same city, from 1982, the alternating format went into effect.
The 2007 marathon was also a representative selection race of the 2007 World Championships in Athletics in Osaka. The total number of participants was set at 30,000. Of that, 25,000 people signed up for the marathon, and 5,000 signed up for the 10K run.